diff options
| author | alc <alc@FreeBSD.org> | 2003-04-27 05:43:03 +0000 |
|---|---|---|
| committer | alc <alc@FreeBSD.org> | 2003-04-27 05:43:03 +0000 |
| commit | a22a4734016282417f667c893bf9c56404c54708 (patch) | |
| tree | c5eb89ec5c862f4cc1f5b561edc8444c7b949839 /sys/vm | |
| parent | 8ce605b935acde6def976e35a718650ffaf7bc7f (diff) | |
| download | FreeBSD-src-a22a4734016282417f667c893bf9c56404c54708.zip FreeBSD-src-a22a4734016282417f667c893bf9c56404c54708.tar.gz | |
Various changes to vm_object_shadow(): (1) update the vm_object locking,
(2) remove a pointless assertion, and (3) make a trivial change to a
comment.
Diffstat (limited to 'sys/vm')
| -rw-r--r-- | sys/vm/vm_object.c | 29 |
1 files changed, 16 insertions, 13 deletions
diff --git a/sys/vm/vm_object.c b/sys/vm/vm_object.c index 087ef98..a3b31f1 100644 --- a/sys/vm/vm_object.c +++ b/sys/vm/vm_object.c @@ -1078,26 +1078,29 @@ vm_object_shadow( vm_object_t source; vm_object_t result; + GIANT_REQUIRED; + source = *object; - vm_object_lock(source); /* * Don't create the new object if the old object isn't shared. */ - if (source != NULL && - source->ref_count == 1 && - source->handle == NULL && - (source->type == OBJT_DEFAULT || - source->type == OBJT_SWAP)) { - vm_object_unlock(source); - return; + if (source != NULL) { + VM_OBJECT_LOCK(source); + if (source->ref_count == 1 && + source->handle == NULL && + (source->type == OBJT_DEFAULT || + source->type == OBJT_SWAP)) { + VM_OBJECT_UNLOCK(source); + return; + } + VM_OBJECT_UNLOCK(source); } /* - * Allocate a new object with the given length + * Allocate a new object with the given length. */ result = vm_object_allocate(OBJT_DEFAULT, length); - KASSERT(result != NULL, ("vm_object_shadow: no object for shadowing")); /* * The new object shadows the source object, adding a reference to it. @@ -1110,7 +1113,8 @@ vm_object_shadow( * shadowed object. */ result->backing_object = source; - if (source) { + if (source != NULL) { + VM_OBJECT_LOCK(source); TAILQ_INSERT_TAIL(&source->shadow_head, result, shadow_list); source->shadow_count++; source->generation++; @@ -1121,6 +1125,7 @@ vm_object_shadow( length = PQ_L2_SIZE / 3 + PQ_PRIME1; result->pg_color = (source->pg_color + length * source->generation) & PQ_L2_MASK; + VM_OBJECT_UNLOCK(source); next_index = (result->pg_color + PQ_L2_SIZE / 3 + PQ_PRIME1) & PQ_L2_MASK; } @@ -1136,8 +1141,6 @@ vm_object_shadow( */ *offset = 0; *object = result; - - vm_object_unlock(source); } /* |
